Gas Mileage Calculator
Gas Mileage Calculator
Calculate your vehicle's fuel efficiency and trip costs
miles
gallons
What is Gas Mileage?
Gas mileage, also known as fuel economy, is a measure of how far a vehicle can travel on a specific amount of fuel. In the United States, it's typically expressed as miles per gallon (MPG). In other countries, it might be expressed as liters per 100 kilometers (L/100km) or kilometers per liter (km/L).
How to Calculate Gas Mileage
To calculate your vehicle's gas mileage:
- Fill your gas tank completely and reset your trip odometer or note the mileage reading.
- Drive normally until you need to refill.
- When refilling, note how many gallons it takes to fill the tank and the trip odometer reading or current mileage.
- Divide the number of miles driven by the number of gallons used.
MPG = Miles driven ÷ Gallons of fuel used
Factors Affecting Gas Mileage
- Driving habits: Aggressive acceleration, high speeds, and frequent braking reduce fuel efficiency.
- Vehicle maintenance: Properly inflated tires, clean air filters, and regular tune-ups improve gas mileage.
- Vehicle weight: Heavier vehicles require more fuel to move.
- Aerodynamics: Wind resistance increases at higher speeds, reducing efficiency.
- Weather conditions: Cold weather, headwinds, and rain can decrease fuel efficiency.
- Terrain: Driving uphill or on rough roads requires more fuel.
- Fuel quality: Different fuel grades can affect performance and efficiency.
Tips to Improve Gas Mileage
- Drive at moderate speeds and avoid rapid acceleration and braking
- Remove excess weight from your vehicle
- Use cruise control on highways to maintain a constant speed
- Keep tires properly inflated
- Replace air filters regularly
- Use the recommended grade of motor oil
- Combine errands to minimize cold starts and short trips
- Turn off the engine when idling for extended periods
- Use air conditioning sparingly
- Keep windows closed at high speeds to reduce drag
Understanding MPG vs. L/100km
Different countries use different units to measure fuel economy:
- Miles per gallon (MPG): Used in the United States and the United Kingdom (though the UK gallon is different from the US gallon).
- Liters per 100 kilometers (L/100km): Used in most European countries and Canada. Lower numbers indicate better fuel efficiency.
- Kilometers per liter (km/L): Used in Japan and some other Asian countries.
To convert between these units:
- MPG (US) to L/100km: 235.214 ÷ MPG = L/100km
- L/100km to MPG (US): 235.214 ÷ L/100km = MPG
- km/L to L/100km: 100 ÷ km/L = L/100km
- L/100km to km/L: 100 ÷ L/100km = km/L